m&oiar  no.  so,  Secono  Series. 


mini  States  Departmenl  oJ 


DIVISION  OF    BNTOMOLOOy! 


MIX   Bl  PI  U  o    I  Kl  I  .lliil'Hi'K. 


hov     ura.:r 


B-green  insect  i-  •  ilu-^eW  £«tfwn 

the  common  ipTrcics  Indenting  regetation,  and  to  the 

int  of  its  triangular  Bhape,  quirk,  active  flighl  n- 

lerable  vaulting  powers.     It  receives  its  peculiar  popular  name  from 

similarity  in  shape  to  the  male  buffalo  or  bison.     Thethon 

pronotum,  is  greatly  \    i  anteriorly,  projecting  laterally  in  t. 

BUt>ng  horns,  and  is  distinctly  triangular,  as  shown  in  the  illustration 

(''"■  '•  "'•     ^  is  this  peculiar  shape  rather  than  any  knowledge  of  its 

habits  that  has  given  it  its  popular  int, rest.     During  tl  tenor 


: 

Moo  I 

ome  importa.it  on  other  and  Btrictly 
economic  grounds.     In  tl  ssippi  VaJle]  ally  from  the  Mis- 

souri   northward,  well   up   into  Canada,  it  has   been   the  i  verv 

grea1  Bin  orchards,  particularly  to  youn  stock 

not,  however,  confining  itself  to  fruit  trees,  but  attacking  also  all 
of  sii  r'"'  '"Jury  is  doe  solely  to  the  cutting  up  of  the  limhe 

by  the  female  with  her  Bawlike  ovipositor  I  fig.  1.  /.  <,)  in  the  deposition 
of  her  eggs,  in  which  particular  the  injury  is  not  unlike  that  caused  by 
the  periodical  cicada,  and  frequently  is  Bcarcely  less   in  amoui 
account  of  the  great  numbers  in  which  the  insect  occurs.     On  • 


L 


a  badly  infested  orchard  in  the  latter  part  of  August,  or  in  September, 
the  buffalo  tree-hopper  will  indicate  its  presence  by  flying  away  with  a 
distinct  buzzing  noise  from  the  trees  approached  and,  as  it  is  a  very  shy 
t,  there  is  some  difficulty  in  coming  close  enough  to  see  it  at  work 
and  observe  its  methods.  Once  well  engaged  in  oviposition,  however, 
it  becomes  for  the  time  being  fearless,  and  may  be  closely  watched, 
even  under  a  hand  lens. 

When;  the  tree-hopper  is  abundant  the  smaller  limbs  of  trees  are  often 
completely  scarified  overtheir  upper  and  Lateral  surfaces,  so  that  the  trees 
become  dwarfed  or  bark-bound,  make  a  sickly  growth,  and  are  rendered 
mOre  liable  to  the  attacks  of  wood-boring  insects.  This  latter  source  of 
injury  was  first  prominently  brought  to  our  notice  in  a  communication 
from  Mr.  J.  A.  Pettigrew,  superintendent  of  Lincoln  Park,  Chicago,  who 
described  the  attacks  of  a  borer  in  the  smaller  branches  of  the  cotton- 
wood,  Papula*  mon  ill  fori,  which  caused  the  limbs  to  break  off  and  fall 
to  the  ground  in  great  numbers.  Examination  of  the  twigs  submitted 
by  him  showed  at  once  that  they  had  been  oviposited  in  very  abun- 
dantly by  the  buffalo  tree-hopper  a  year  or  two  before,  and  that  the  old 
scars  from  the  egg-punctures  of  this  insect  had  furnished  favorable  con- 
ditions for  the  attacks  of  a  wood-boring  beetle,  Oberea  schaumii  Lee. 
This  beetle  had  deposited  its  eggs  in  the  diseased  spots  left  by  the 
Ceresa,  and  the  larvae  of  the  beetle  had  burrowed  up  and  down  the  twigs, 
weakening  them  and  causing  them  to  break  off  and  fall  as  described. 
Healthy  twigs  would  be  distasteful  or  unsatisfactory  to  this  insect,  but 
the  diseased  condition,  and  particularly  the  dead  spots  left  by  the  Ceresa, 
furnish  the  very  conditions  most  favorable  for  this  wood-borer,  as  simi- 
lar injuries  do  for  many  other  wood-boring  insects. 

HABITS   AND   LIFE    HISTORY. 

.  The  habits  and  life-history  of  the  buffalo  tree-hopper  are  as  follows : 
The  adult  insect  chooses  as  a  nidus  for  its  eggs  the  twigs,  preferably 
those  of  two  or  three  years'  growth,  of  various  trees,  particularly  the 
apple,  willow,  cottonwood,  maple,  etc.,  confines  itself  in  general  to  the 
upper  surface  of  the  twigs,  and  works  more  abundantly  on  the  south 
side  of  the  tree  than  on  the  north,  although  in  this  respect  the  prevail- 
ing winds  and  other  conditions  influence  the  insect.  The  eggs  are 
deposited  quite  as  readily  in  the  new  growth  of  old  trees,  as  in  young 
trees,  but  the  damage  is  much  more  noticeable  in  the  latter  case.  The 
eggs  are  placed  in  small  compound  groups  of  from  6  to  12  eggs  each, 
arranged  in  two  nearly  parallel  or  slightly  curved  slits  extending  in  the 
direction  of  the  twig  about  three-sixteenths  of  an  inch  in  length,  and 
separated  by  one-eighth  inch  or  less  of  bark  (fig.  2,  h) . 

In  depositing  the  eggs  the  bark  is  cut  by  the  ovipositor  in  such  a 
way  that  the  narrow  bark  intervening  between  the  two  incisions  is 
cut  entirely  loose.  This  has  a  very  important  bearing  on  the  subse- 
quent condition  of  the  wounds  made  by  the  insect  in  oviposition.  The 
object  is  doubtless  to  cause  a  deadening  of  the  wood  between  the  two 
rows  of  eggs,  to  prevent  their  being  crushed  and  choked  out  by  the  sub- 
sequent rapid  growth  of  the  twig,  and  it  is  due  to  this  peculiarity  that 
the  injury  later  assumes  so  serious  a  nature.  A  single  incision  made 
by  the  insect  to  contain  its  eggs  would  heal  over  and  cause  little  after- 
damage,  hut  with  the  combination  of  two  incisions  and  the  killing  of 
the  intervening  bark,  causing  it  to  adhere  to  the  wood,  a  large  scar  is 


-«-■ 


¥ 


produced,  which,  with  ench  subsequent  year-  growth,  enlarges  and 
ultimately  assunx  -  an  oval  form,  the  dead  bark  ol  the  center  breaking 
out.     Aftei    i  i'  hich  have  been  thickly  worked  on  \<\ 

the  insect   become  verj  Bcabby  and  rough,  are  easily  broken  off  by  the 

I,  mid  arc  very  liable  i"  attack  by  wood-boring  insects  (fig.  '1. 
The  adults  first  appear  about  the  middle  of  July,  and  become  n 
numerous  during  ml  September.     They  begin  oviposition  about 

the  middle  ol  or  oven  earlier,  and  continue  this  work  until  they 

arc  killed  by  the  frosts  of  early  winter,  sometimes  working  as  late  as  lin- 
en.I  of  October.  The  number  ol  leposited  by  a  Bingle  female 
tin  UK),  and  possibly  200.  The  eggs  remain  unchanged,  or  dor- 
mant, in  the  twigs  until  the  following  spring,  hatching  in  May  <>r  early 
in  June.  The  egg  is  about  one-sixteenth  of  an  inch  long,  Blightly 
curved,  tapering  toward  the  outer  end  and  mine  rounded  at  the  inner 
one.  It  i<  without  markings, of  a  dirty 
whitish  color,  and  cylindrical  excepl 
as  more  or  less  angulated  by  the  pres- 
sure of  the  wood  and  the  adjacent  • 
The  eggs  of  the  buffalo  tree-hopper 

tuhject  to  the  attacks  of  at  least 
two  minute  egg  parasites,  which  often 
do  much    to  keep   the  insect    in  check. 

In  general  characteristics  the  larva' 

and  nymphs  resemble  the  adults,  but 

are    wingless    and    covered    along    the 

lly  with  numerous  forked 

or  barbed  projections. 

POOD    PLANTS. 

The  larva1  and  pupa  .  as  well  as  the 
adults,  feed  on  all  sorts  of  succulent 
ition,  such  as  weed.-  and  garden 
vegetables,  and  are  apparently  not  par- 
ticularly fond  of  the  apple,  much  pre- 
ferring   the    more    Bucculent    annual 

plants.      Mr.  J.  G.  Jack  reports  that  h<  »•*  ';' 

.  ,      .  ,    i.      .      j.  ,  npi>le    showing,   a,    tcmulc    at    work;    /.. 

found  the  adult.-  Feeding  on  the  young 

•iinl   ton.ler  <h,>,i1<  nf  thp  nnnlp    neirtlie        witheggaln  position.  Blight): 

ana  tena<  r  bdoois  oi  me  appie,  nt  ar  m* 

ground,  hv  which   I  suppose  he  means 

,  ,  on  oldei 

the    watershoots,    for    certainly,    after 

very  careful  and   repeated  observations  in   an  orchard  which   wat 
infested  as  to    he  nearly  ruined.  I    failed   to   find   any  indication   of  the 
feeding   of  larva    or   adults  on   apple.      The   injury,  at    any  rate,  in  this 
direction,  to  fruit  and  shade  trees  i.-  practically  not   worth  considering. 


REMEDIES    AND    PREVENTIVES 


The  destruction  of  the  insects  themselves  is  difficult  and  in  genera] 
impracticable,  because  the  larva-  and  adults  feed  on  all  sorts  of  vege- 
tation and  are  very  widely  distributed.  The  adults,  also,  arc  too  active 
and  quick  of  fiighl  to  be  successfully  reached  by  caustic  washes ;  and 

spraying   to  destroy  tie-  early  stages    i-  ordinarily  out   of   the  question, 
because  it  would  necessitate  extending   the  treatment    to    all   surround- 


UNIVERSITY  OF  FLORIDA 


3  1262  09216  4655 

ing  vegetation,  and,  as  the  adults  are  strong  flyers,  even  this  would 
give  no  absolute  security. 

The  limiting  of  the  amount  of  foreign  vegetation  about  and  in  orchards 
and  nurseries  is  an  excellent  precaution,  and  little  damage  may  be 
anticipated  where  the  ground  between  the  trees  is  kept  clean  and  con- 
stantly cultivated.  The  larvae  and  pupa-  under  these  conditions  will  be 
starved  out.  The  orchard  in  which  the  writer  first  studied  this  insect, 
and  which  was  so  thoroughly  infested  as  to  be  seriously  injured,  was 
one  which  had  been  neglected  for  a  number  of  years  and  was  full  of 
weeds  and  succulent  undergrowth,  furnishing  conditions  under  which  an 
unusual  multiplication  of  the  Ceresa  had  taken  place  during  a  number 
of  years.  Surrounding  and  better  kept  orchards  showed  little,  if  any, 
damage. 

Vigorous  pruning  in  the  fall  or  winter  should  be  given  trees  which 
have  been  cut  up  to  any  extent,  and  this  with  clean  culture  should 
reduce  the  insect  to  small  numbers.  It  is  possible  that  some  good 
could  be  accomplished  by  planting  trap  plants  between  the  rows  ol 
trees,  such  as  beans  or  other  similar  summer  crops,  which  could  be 
sprayed  with  the  stronger  mixtures  of  the  kerosene  and  soap  emulsion 
when  the  larvae  became  numerous,  or  about  the  first  of  July,  but  the 
more  promising  method  is  the  cultural  one  already  described. 

C.  L.  Marlatt, 
First  Assistant  Entomologist. 

Approved : 

James  Wilson, 

Secretary  of  Agriculture. 

Washington,  D.  C,  May  10,  1897. 

O 


